Pressure relief valve



1 Sept. 29, 1936. BQYNTQN 2,055,465 I PRESSURE RELIEF VALVE Filed Sept, 50, 1932 ,Alekahier Bojntb n 7 W I ,5, a QQM Patented SepL,2 9,1936' v I l a 1 v 2 UNITED STATES" PATENT OFFICE,

PRESSURE BELIEF VALVE Alexander Boynton, San Antonio, Tex, assignor to Chas. A. Beatty," San Antonio, Tex.

Application September 30,1932, Serial No. 635,542 comma, (01. 137-53) My invention relates to pressure relief valves wall 16, which is beveled at I! adjacent an openadapted to automatically operate to relieve ex-' ing to provide a seat for the tapered valve memcessive pressures within a container. It finds her i8. its particular application to use on boilers, pipe Said wall closes the lower end of the housing 5 lines, oil and gas wells and similar containers except ior'the valve controlled opening there- 5 in which gas or liquids are confined under presthrough forming the seat II. The housing is sure. threaded at its lower end for-engagement with It is an object oi the invention to provide a a fluid conducting line or container for the exvalve which is supported'upon a longitudinally cess fluid. l0 extensible member adapted to be acted upon by The valve i8 is mounted at the lower end or 10. the pressure in the container to control the a longitudinally extensible bellows or multiple position of the valve relative to the emergency diaphragm member i9. Said bellows member outlet. has a spiral corrugation thereon extending from I desire to provide a bellows or diaphragm ele-, the upper to the lower end and is adapted to ment to be supported in a chamber connected, b mp ss d or xpand d to xtend or con- 15 with the container, wen. or line which will be tract the same longitudinally. The corrugations acted upon by the pressure fluid to be contracted on the bellows may be ring-shaped instead or or elongated by the varying pressures therein to spiral, as will be obvious, as both forms or belraise or lower the valve relative to the seat in lows maybe purchased.- Said bellows member the outlet. The invention resides in thepartics made p Of thin sheet metal a d he allace ular structure oi the controlling device which thereof may be composed of o o more thickdetermines the position or the valve in the vent h e f metal- The pp r n is old red or to atmosphere, or discharge into another line welded at 20 within the lower end of the head or container. r is upon the stem Hi. It makes a fluid-tight seal In the drawing herewith, Fig. 1- is a central with said stem to prevent leakage oi fluid at that 25, longitudinal'section through a structure employpoint. The outer end of the bellows member is lng my invention; and welded at 2i to a longitudinally extending flange I 1 Fig. 2 is a transverse section on the plane 2--2 pon he ln 22 h aded n c nnection with of Fig. 1. i i the valve head l8. It will be noted from Fig. 1

In the drawin 1 have h wn a, fitting I, that said valve head is screwed within the ring 30 which has a threaded opening 2 for connection 22 and is sealed into enga therewith y in a line 3, which is to be understood as com- .a bond of soldering or welding material shown ing from a. w n, pipe l boiler or Other o at .23. There is a duct or channel 24, formed trainer in which fluid under pressure pxists or in the valve a w e e e w d mamay exist. The fitting is T-shaped having one er l is l ed in position, forms a ut t f om. 35

end'iormed it threaded opening .intqwhjch the interior or the bellows member. is screwed a lug 5, s id plug i fo d ith There is a spring 25 withinthe bellows member a lower shoulder between which and the outer fi in at e d wi hin a rece s 26 in the head end of the fitting is clamped a packing washer It or the stem. At the lower end it bears against 40 t. The outer end or the lug is recessed to term the upper shank of the valve head It. It is 40 a stufllng box including a packing member I, a under slight compression tending to elongate the gland 8 and a threaded cap 9 bearing on the bellows and hold the valve within the seat i'l. gland to force the same into contact with the In assembling the bell ws, i is br zed packing. or welded to the head i3 of the stem, and to the A rotatable stem III is extended inwardly 1 ring 22 at its opposite end, the valve head It 45 through the stumng box and has a, threaded enbeing removed; The spring 25 is then placed in gagement within an axial passage ll through position and the bellows arranged with the valve the plug. The outer end of the stern has a hanend upwardly. Liquid, such as glycerine, is then die l2 thereon by means of which the stem may poured within the bellows member to entirelyfill be rotated to screw the same longitudinally in the same. The valve head i8 is then screwed in 50 the plug to move the control head II on the stem position and the bellows member is compressed longitudinally in the fitting i." a t longitudinally to its maximum compression in The other arm of the T is threaded at It for ordinary operation. Excess glycerine will then connection withthe tubular housing Ii. Said escape through the channel 24. The bellows will housing has adjacent its lower end an annular then be released and the spring will tend to force 55 cept for a slight permanent set in the walls of the bellows member, due to the compressionof the same. The bond of soldering, brazing or welding material 23 will then be applied and the bellows assembly will be ready for installation as shown in Fig. 1.

I provide a guide sleeve 26 about the bellows .member to protect the same against erosion of fluids and abrasive substances therein while in use. This sleeve 26 has a threaded engagement at its upper end with the ring or washer 28, which is preferably threaded above the head 13 upon the stem it. The sleeve extends downwardly in spaced relation relative to the bellows ing. I may employ an indicator in the shape of a gauge 29 to show the pressures within the safety device. i i

In operation the valve will be adjusted through 1 the stem H) to engage within the seat I! under pressures which are approaching the maximum for safety or such as may be desired. The valve will then close the outlet and will prevent the escape of fluid from the line when said pressures are not excessive. The device will operate automatically thereafter and when fluid in the line 3 attains a maximum pressure which -is above the limit of safety or more than desired, the said pressure will be exerted against the walls of the.

multiple diaphragm l9 and collapse the same slightly, tending to shorten the length of the bellows member and raise the valve from its seatto allow escape of the pressure fluid. When the pressures within the housing have declined to within a limit of safety to that which may be de sired the bellows member be again extended longitudinally to close the valve.

The use of some such liquid as glycerine within the bellows member allows this device to be used in situations where high pressures are encountered. There is a slight cushion of air which enters within the bellows after the same is compressed and allowed to extend in assembling.

The bellows is, however, nearly full of glycerine or other liquid and when the bellows is partially collapsed underpressures which are excessive,

. 2,050,405 --it back to its original position. This it will do extending to rupture the bellows or diaphragm, the glycerine on the interior will form a support for the walls, preventing collapse and resisting pressures on the exterior of the bellows member much in excess of those ordinarily considered safe. It is not essential to have a cushion of air above the liquid filler. A vacuum there will cause the bellowsto cushion upon the liquid instead of air and the operation is much the same. I have found that bellows with a wall thickness of .008 of an inch will withstand pressures as high as five thousand pounds per square inch without damage.

The spring which is employed should be considerably longer than the bellows in orderthat the force required to compress the spring in assembly will not increase as the spring is compressed as rapidly 'as this force would increase were the free length of the spring not greater than the free length of the bellows. With this safety valve thus constructed I have produced a structure in which the valve is deli-1 cately adjusted to operate positively when the pressures become excessive within the well, boiler, line, or other container. It will be capable of adjustment for different pressures with no further manipulationthan the'rotation of the stem it.

It is simple and reliable in construction eflicient in operation,

What I claim as new is:

1. A pressure relief valve including a housing and is adapted to be connected with a container of fluid under pressure, a bellows-shaped metal diaphragm member longitudinally of said'housing, an outlet in said housing, a valve on the lower end of said bellows member adapted on compression of said member to open said outlet, a stem to which the other end of said bellows member isv non-rotatably fixed, means to adjust said stem and bellows member longitudinally to set said valve, and means in said bellows member including a charge of liquid incompletely filling said member to resist. undue compression thereof under pressure.

2 A pressure relief valve including a housing adapted to be connected with a container of fluid under pressure, a bellows-shaped metal diaphragm member longitudinally of said housing, an outlet in said housing, a valve on the forward end of said bellows member controlling said outlet, a stem to which the other end of said bellows member is fixed, a protecting sleeve on said stem enclosing said bellows member, means "to adjust said stem and bellows member longitudinally to set said valve and a spring in said bellows member tending to elongate said member to hold said valve seated.

ALEXANDER BOYNTON. 

